Prevalence of colonization with multidrug-resistant bacteria in communities and hospitals in Kenya

Abstract

We estimated the prevalence of extended-spectrum cephalosporin-resistant Enterobacterales (ESCrE), carbapenem-resistant Enterobacterales (CRE), and methicillin-resistant Staphylococcus aureus (MRSA) in communities and hospitals in Kenya to identify human colonization with multidrug-resistant bacteria. Nasal and fecal specimen were collected from inpatients and community residents in Nairobi (urban) and Siaya (rural) counties. Swabs were plated on chromogenic agar to presumptively identify ESCrE, CRE and MRSA isolates. Confirmatory identification and antibiotic susceptibility testing were done using the VITEK®2 instrument. A total of 1999 community residents and 1023 inpatients were enrolled between January 2019 and March 2020. ESCrE colonization was higher in urban than rural communities (52 vs. 45%; P = 0.013) and in urban than rural hospitals (70 vs. 63%; P = 0.032). Overall, ESCrE colonization was ~ 18% higher in hospitals than in corresponding communities. CRE colonization was higher in hospital than community settings (rural: 7 vs. 1%; urban: 17 vs. 1%; with non-overlapping 95% confidence intervals), while MRSA was rarely detected (≤ 3% overall). Human colonization with ESCrE and CRE was common, particularly in hospitals and urban settings. MRSA colonization was uncommon. Evaluation of risk factors and genetic mechanisms of resistance can guide prevention and control efforts tailored to different environments.

Figure 1

Heatmap showing the proportion of resistant isolates among ESCrE for ten of the seventeen antibiotics tested. Increasing color intensity denotes increasing proportion of resistant isolates. Seven are not shown because all isolates were fully resistant to ceftriaxone, ampicillin, and cefazolin and none had intermediate or complete resistance to amikacin, ertapenem, imipenem and meropenem. Heatmap includes 1345 E. coli (hospital = 492, community = 863) and 442 Klebsiella oxytoca and K. pneumoniae pooled (hospital = 280 hospital, community = 162). Antibiotics: aztreonam (Atm), ciprofloxacin (Cip), cefepime (Fep), gentamicin (Gen), moxifloxacin (Mxf), nitrofurantoin (Nit), ampicillin/sulbactam (Sam), sulfamethoxazole/trimethoprim (Sxt), tigecycline (Tig), and tobramycin (Tob).

Figure 2

Heatmap showing the proportion of resistant isolates among CRE for 12 of the 17 antibiotics tested. Increasing color intensity denotes increasing proportion of resistant isolates. The three carbapenems tested (ertapenem, imipenem and meropenem) are not shown. Ampicillin and cefazolin are also not shown because isolates were fully resistant. Heatmap includes 96 E. coli (hospital = 86, community = 10), 11 Klebsiella oxytoca and K. pneumoniae pooled, and 18 Enterobacter aerogenes and E. cloacae pooled. Antibiotics: amikacin (Amk), aztreonam (Atm), ciprofloxacin (Cip), ceftriaxone (Cro), cefepime (Fep), gentamicin (Gen), moxifloxacin (Mxf), nitrofurantoin (Nit), ampicillin/sulbactam (Sam), sulfamethoxazole/trimethoprim (Sxt), tigecycline (Tig), and tobramycin (Tob).